Hotlist Slow: Remove extra thread pool created by VolumeMountWatcherWin.

components/storage_monitor/volume_mount_watcher_win.cc

Index: components/storage_monitor/volume_mount_watcher_win.cc
diff --git a/components/storage_monitor/volume_mount_watcher_win.cc b/components/storage_monitor/volume_mount_watcher_win.cc
index fd3e6a5a4ad969eba086319ab445af72bc3485ad..6a89e1a1e01e4800f41208533eecfe85d2430e2a 100644
--- a/components/storage_monitor/volume_mount_watcher_win.cc
+++ b/components/storage_monitor/volume_mount_watcher_win.cc
@@ -34,6 +34,8 @@ namespace {
 
 const DWORD kMaxPathBufLen = MAX_PATH + 1;
 
+const char kDeviceInfoTaskRunnerName[] = "device-info-task-runner";
+
 enum DeviceType {
   FLOPPY,
   REMOVABLE,
@@ -324,18 +326,12 @@ void EjectDeviceInThreadPool(
 
 }  // namespace
 
-const int kWorkerPoolNumThreads = 3;
-const char* kWorkerPoolNamePrefix = "DeviceInfoPool";
-
 VolumeMountWatcherWin::VolumeMountWatcherWin()
-    : device_info_worker_pool_(new base::SequencedWorkerPool(
-          kWorkerPoolNumThreads, kWorkerPoolNamePrefix)),
-      notifications_(NULL),
-      weak_factory_(this) {
-  task_runner_ =
-      device_info_worker_pool_->GetSequencedTaskRunnerWithShutdownBehavior(
-          device_info_worker_pool_->GetSequenceToken(),
-          base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN);
+    : notifications_(NULL), weak_factory_(this) {
+  base::SequencedWorkerPool* pool = content::BrowserThread::GetBlockingPool();
+  device_info_task_runner_ = pool->GetSequencedTaskRunnerWithShutdownBehavior(
+      pool->GetNamedSequenceToken(kDeviceInfoTaskRunnerName),
+      base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN);
 }
 
 // static
@@ -361,7 +357,7 @@ void VolumeMountWatcherWin::Init() {
   // so a posted task from the constructor would never run. Therefore, do all
   // the initializations here.
   base::PostTaskAndReplyWithResult(
-      task_runner_.get(), FROM_HERE, GetAttachedDevicesCallback(),
+      device_info_task_runner_.get(), FROM_HERE, GetAttachedDevicesCallback(),
       base::Bind(&VolumeMountWatcherWin::AddDevicesOnUIThread,
                  weak_factory_.GetWeakPtr()));
 }
@@ -374,7 +370,7 @@ void VolumeMountWatcherWin::AddDevicesOnUIThread(
     if (ContainsKey(pending_device_checks_, removable_devices[i]))
       continue;
     pending_device_checks_.insert(removable_devices[i]);
-    task_runner_->PostTask(
+    device_info_task_runner_->PostTask(
         FROM_HERE,
         base::Bind(&VolumeMountWatcherWin::RetrieveInfoForDeviceAndAdd,
                    removable_devices[i], GetDeviceDetailsCallback(),
@@ -503,7 +499,6 @@ void VolumeMountWatcherWin::SetNotifications(
 
 VolumeMountWatcherWin::~VolumeMountWatcherWin() {
   weak_factory_.InvalidateWeakPtrs();
-  device_info_worker_pool_->Shutdown();
 }
 
 void VolumeMountWatcherWin::HandleDeviceAttachEventOnUIThread(
@@ -548,9 +543,9 @@ void VolumeMountWatcherWin::EjectDevice(
     return;
   }
 
-  task_runner_->PostTask(
-      FROM_HERE,
-      base::Bind(&EjectDeviceInThreadPool, device, callback, task_runner_, 0));
+  device_info_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&EjectDeviceInThreadPool, device, callback,
+                            device_info_task_runner_, 0));
 }
 
 }  // namespace storage_monitor